System and method to generate a waveform in a communication network

ABSTRACT

Embodiments of the present disclosure relate to a communication system to generate a waveform by multiplexing multiple user data. The system comprises at least one transceiver, a multiplexer and a processor. The at least one transceiver configured to perform at least one of receiving a plurality of data from a transmitter, and transmitting a generated waveform to a destination. The multiplexer configured to multiplex a plurality of data associated with a plurality of users, to generate multiplexed data. The processor is configured to perform a rotation operation on the multiplexed data to produce a rotated data. Also, the processor is configured to transform the rotated data using Fourier transform to produce transformed data. Further, the processor is configured to map the transformed data using a predefined number of subcarriers to produce a mapped data sequence and thereafter, process the mapped data sequence to generate the waveform.

TECHNICAL FIELD

Embodiments of the present disclosure are related, in general tocommunication, but exclusively relate to system and method formultiplexing multiple user data using one of a single waveform andmultiple waveforms.

BACKGROUND

Orthogonal Frequency Division Multiplexing (OFDM) is widely used in manywireless systems for both modulation and multiple access. The OFDMwaveform has high peak-to-average-power-ratio (PAPR), and thereforerequires a high-power amplifier back-off during transmission. DiscreteFourier Transform pre-coded OFDM (DFT pre-coded OFDM) was suggested inthe uplink of LTE (Long-Term-Evolution) standards to reduce the PAPR.While OFDM exhibits close to 9 dB PAPR, DFT pre-coded OFDM has PAPR inthe range of 5.0-6.0 dB for QPSK (Quadrature-Phase-Shift-Keying)modulation. However, it is inherently power inefficient modulation.

Hence, there is a need of a solution for a method and system tomultiplex data of a multiple users and generate a pre-coded waveformwith low PAPR.

SUMMARY

The shortcomings of the prior art are overcome and additional advantagesare provided through the provision of method of the present disclosure.

Additional features and advantages are realized through the techniquesof the present disclosure. Other embodiments and aspects of thedisclosure are described in detail herein and are considered a part ofthe claimed disclosure.

In an aspect of the present disclosure, method of generating a waveformin a communication network is provided. The method comprisesmultiplexing, by a communication system, a plurality of data associatedwith a plurality of users, to generate multiplexed data. Also, themethod comprises performing a rotation operation on the multiplexed datato produce a rotated data and transforming the rotated data usingFourier transform to produce transformed data. Further, the methodcomprises mapping the transformed data using a predefined number ofsubcarriers to produce a mapped data sequence and processing the mappeddata sequence to generate the waveform.

Another aspect of the present disclosure is a communication system togenerate a waveform in a communication network. The system comprises atleast one transceiver, a multiplexer and a processor. The at least onetransceiver configured to perform at least one of receiving a pluralityof data from a transmitter, and transmitting a generated waveform to adestination. The multiplexer configured to multiplex a plurality of dataassociated with a plurality of users, to generate multiplexed data. Theprocessor is configured to perform a rotation operation on themultiplexed data to produce a rotated data. Also, the processor isconfigured to transform the rotated data using Fourier transform toproduce transformed data. Further, the processor is configured to mapthe transformed data using a predefined number of subcarriers to producea mapped data sequence and thereafter, process the mapped data sequenceto generate the waveform.

The foregoing summary is illustrative only and is not intended to be inany way limiting. In addition to the illustrative aspects, embodiments,and features described above, further aspects, embodiments, and featureswill become apparent by reference to the drawings and the followingdetailed description.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this disclosure, illustrate exemplary embodiments and, togetherwith the description, serve to explain the disclosed principles. In thefigures, the left-most digit(s) of a reference number identifies thefigure in which the reference number first appears. The same numbers areused throughout the figures to reference like features and components.Some embodiments of device or system and/or methods in accordance withembodiments of the present subject matter are now described, by way ofexample only, and with reference to the accompanying figures, in which:

FIG. 1A shows an illustration of a communication system to generate awaveform by multiplexing multi-user data, in accordance with someembodiments of the present disclosure.

FIG. 1B shows an illustration of a generalized precoded OFDM (Orthogonalfrequency-division multiplexing) (GPO) system to generate a waveform, inaccordance with some embodiments of the present disclosure;

FIG. 2 illustrates a block diagram of GPO receiver, in accordance withsome embodiment of the present disclosure; and

FIG. 3 shows a flowchart illustrating a method of generating a waveformusing communication system as shown in FIG. 1, in accordance with someembodiments of the present disclosure.

DETAILED DESCRIPTION

In the present document, the word “exemplary” is used herein to mean“serving as an example, instance, or illustration.” Any embodiment orimplementation of the present subject matter described herein as“exemplary” is not necessarily to be construed as preferred oradvantageous over other embodiments.

While the disclosure is susceptible to various modifications andalternative forms, specific embodiment thereof has been shown by way ofexample in the drawings and will be described in detail below. It shouldbe understood, however that it is not intended to limit the disclosureto the particular forms disclosed, but on the contrary, the disclosureis to cover all modifications, equivalents, and alternative fallingwithin the spirit and the scope of the disclosure.

The terms “comprises”, “comprising”, or any other variations thereof,are intended to cover a non-exclusive inclusion, such that a setup,device or method that comprises a list of components or steps does notinclude only those components or steps but may include other componentsor steps not expressly listed or inherent to such setup or device ormethod. In other words, one or more elements in a device or system orapparatus proceeded by “comprises . . . a” does not, without moreconstraints, preclude the existence of other elements or additionalelements in the device or system or apparatus.

The present disclosure relates to a system and method of generating awaveform in a communication network. The system comprises a multiplexingmodule to multiplex a plurality of data associated with a plurality ofusers and generate multiplexed data. Also, the system is configured toperform a rotation operation on the multiplexed data to produce arotated data and transform the rotated data using Fourier transform toproduce a transformed data. Further, the system maps the transformeddata using a predefined number of subcarriers to produce a mapped datasequence. Thereafter, the system processes the mapped data sequence togenerate a waveform.

In the following detailed description of the embodiments of thedisclosure, reference is made to the accompanying drawings that form apart hereof, and in which are shown by way of illustration specificembodiments in which the disclosure may be practiced. These embodimentsare described in sufficient detail to enable those skilled in the art topractice the disclosure, and it is to be understood that otherembodiments may be utilized and that changes may be made withoutdeparting from the scope of the present disclosure. The followingdescription is, therefore, not to be taken in a limiting sense.

FIG. 1A shows an illustration of a communication system 100 to generatea waveform by multiplexing multi-user data, in accordance with someembodiments of the present disclosure.

As shown in FIG. 1A, the communication system 100 includes a generalizedpre-coded OFDM (Orthogonal frequency-division multiplexing) (GPO) system102, a multiplexer 104, a plurality of modulators 106-1, 106-2, . . .106-N, and a plurality of channel coders 108-1, 108-2, . . . 108-N. Thecommunication system 100 is also referred as a base station (BS),transmitter system, transmitter, generalized pre-coded (OrthogonalFrequency Division Multiple Access) OFDM (GPO) transmitter or GPOsystem. The communication system 100 is configured to generate waveform,also referred as data or signals, for multi-users by multiplexing datain downlink, in accordance with some embodiments of the presentdisclosure.

Also, as shown in FIG. 1A, a plurality of data, also referred as userdata i.e. user-1 data 110-1, user-2 data 110-2, . . . , user-N data110-N, is associated with a plurality of users, are multiplexed in timedomain using the multiplexer 104 before feeding the data to the GPOsystem 102. The plurality of data is collectively referred as pluralityof user data 110. For example, the plurality of data 110-1, 110-2, . . ., 110-N belongs to multiple cell edge users (not shown in Fig.) may bemultiplexed using one of BPSK or QPSK modulation. Each of the pluralityof user data (110-1, 110-2, . . . , 110-N) is coded by a correspondingchannel coder 108-1, 108-2, . . . 108-N. For the case of BPSK, it ispreferable that all users share the same BPSK modulation so that GPOgenerates a signal with low PAPR. Each user can apply its own code rate,encoding method for BPSK. Further, the length of the data between theusers may be unequal.

FIG. 1B shows an illustration of a generalized precoded OFDM (Orthogonalfrequency-division multiplexing) (GPO) system to generate a waveform, inaccordance with some embodiments of the present disclosure.

As shown in FIG. 1B, the GPO system 102 includes a processor 120 and amemory 122. The memory 122 may be communicatively coupled to theprocessor 120. The processor 120 may be configured to perform one ormore functions of the GPO system 102 for generating a waveform, using aplurality of data associated with a plurality of users. In oneimplementation, the GPO system 100 may comprise modules 124 forperforming various operations in accordance with the embodiments of thepresent disclosure.

In an embodiment, the GPO system 102 receives input data from themultiplexer 104, whose input is the plurality of data associated withthe plurality of users. The plurality of data is also referred as inputdata 112.

In some embodiment, the input data 112 may be processed by one or moremodules 124 of the GPO system 102. In some implementation, the one ormore modules 124 may be stored with the memory 122. In anotherimplementation, the one or more modules 124 may be communicativelycoupled to the processor 120 for performing one or more functions of theGPO system 102. The modules 124 may include, without limiting to, arotation module 130, a Discrete Fourier Transform (DFT) spreading module132, a frequency domain filter 134, an inverse Fourier Transform module136 and an output module 138.

The rotation module 130 performs constellation rotation on input data112 to produce a rotated data. The constellation rotation operationperformed rotates the input data 112 by 180/Q degrees betweenconsecutive data symbols, where Q is size of modulation alphabet. Theinput data 112 is one of a Binary Phase Shift Keying (BPSK) sequence andQuadrature Phase Shift Keying (QPSK) sequence. In one embodiment, theinput data is binary phase-shift keying (BPSK), of predefined length andthe phase difference between consecutive data symbols is 90-degrees.

The DFT spreading module 132 transforms the rotated data into frequencydomain using an M-point DFT (Discrete Fourier Transform) to produce atransformed date, also referred as a DFT output data sequence ortransformed output data sequence, wherein M is length of data sequence.In an embodiment, the DFT size is predefined. The DFT module may furtherspread the DFT output by repeatedly concatenating the transformed outputdata sequence ‘s’ times where ‘s’ is an oversampling factor. The valueof “s” may be greater than or equal to 1.

The frequency domain filter 134, also referred as subcarrier filter orsubcarrier mapper, performs the frequency domain pulse shaping orsubcarrier level filtering on the output of DFT spreading module 132,which is followed by mapping of frequency domain pulse shaped data tosubcarriers. The frequency domain filter 134 uses one of contiguoussubcarrier mapping, interleaved subcarrier mapping, distributedsubcarrier mapping. For the uplink operation, the frequency domain pulseshaping and mapping is a user specific operation. Different users mayuse different mapping rules. In some embodiments, the frequency domainpulse shaping and mapping rule are fixed operations. The user specificfrequency shift or offset used by the subcarrier mapping operationdetermines whether users use frequency orthogonal, i.e. non-overlappingsubcarriers of users, or frequency non-orthogonal i.e. partially orfully overlapping subcarriers among users.

The inverse Fourier transform module 136, also referred as inverse DFTmodule or inverse fast Fourier transform (IFFT) performs the inversetransform on the output of the frequency domain filter 134 output, togenerate a time domain signal.

The output module 138 performs at least one of addition of cyclicprefix, cyclic suffix, windowing, windowing with overlap and addingoperation, and frequency shifting on the time domain signal to generatea waveform, also referred as an output or output waveform 140. Also, theoutput waveform 140 is fed to a digital to analog converter (DAC) togenerate analog precoded waveform.

In one embodiment, the output module 138 uses a predefined number ofsamples (Ncp) of the time domain sequence, output of inverse Fouriertransform module 136, to append the Ncp sample at the beginning of thetime domain data sequence to obtain CP (cyclic prefix) time domainsequence. In another embodiment, a multiplicative windowing operation isperformed by the output module 138 on the CP time domain sequence toobtain windowed CP time domain sequence. The window function may bechosen such that the window takes zero value during the beginning of theCP time domain sequence and raises to unit value during the portion ofthe CP. Also, the window starts decaying at some point towards the endof the CP time domain sequence and decays to zero at the edge of the CPtime domain sequence. The window function is preferably chosen to besymmetric function.

In one embodiment, the output module 138 is configured with both CP andcyclic post fix (CS). CS refers to addition of first Ncs samples of thetime domain sequence and appends Ncs samples to the beginning of thetime domain data sequence to obtain CP and CS time domain sequence. Inan embodiment, the value of Ncs may exceed the CP value. Also, theoutput module 138 performs time domain filtering on the output from theinverse Fourier transform module 136, using windowing and overlap addoperation to reduce the OBE.

In an embodiment, the GPO system 102 generates a waveform is any of twooperational modes, i.e. GPO with excess bandwidth (BW) mode and GPOwithout excess BW. For the GPO system 102 with the excess BW mode, thefrequency domain filter 134 is configured with a frequency domain pulseshaping filter (FDPSF) that occupies certain excess bandwidth (BW). Thedata from plurality of users is multiplexed with M-subcarrier spacing,M-being the number of occupied subcarriers for each user, so that excessBW does not cause a loss in bandwidth efficiency. The excess BW maycause mutual interference between users that are frequency multiplexedin adjacent resources. The amount of interference caused by the FDPSF islow, such that there is no significant reduction in bit error rate(BER). In an embodiment, a linearized Gaussian minimum shift keying(GMSK) pulse is oversampled with an oversampling factor “os”, whichprovides the FDPSF an excess BW of “os times M” i.e. “os” times thenumber of occupied subcarriers.

For example, when BW=infinity, and os=3, then the output of thefrequency domain filter 134 is a minimum shift keying (MSK) signal withnear constant envelope and smooth phase trajectories within one OFDMsymbol. In another example, when BT=0.3, and os=2, a signal similar tothat of linearized GMSK is obtained by the frequency domain filter 134.

For example, for the GPO without excess BW mode, let os=1 and the FDPSFdo not use excess BW. Then, this mode leads to a frequency orthogonaluser multiplexing i.e. the PAPR of the signal generated using os=1 isgenerally higher than for the case of os>1.

In one example embodiment, let a base station (BS) frequency multiplexesa number of users in the uplink, here the BS is the communication system100. Therefore, number of subcarriers of the users occupied is less thanthe total number of subcarriers. However, the user may use a large IFFTsize in the inverse Fourier transform module 136, with sufficient numberof zeros added for null subcarriers, to generate a signal at a highsampling rate. The IFFT size is dependent on total number ofsubcarriers, used by the frequency domain filter 134 configured in thecommunication system 100. The output module 138 is configured to add acyclic prefix (CP) before transmission of the generated output waveform140. Length of the CP added is same for all users and is designed tohandle the delay spread for full band allocation.

In another embodiment, the number of allocated subcarriers is kept to afixed maximum value so that the user transmits a signal that occupies asub-band. In this case, the user may use an IFFT size such that the usergenerates a narrow band signal. In this case, the user generates thesignal at a lower sampling rate using a smaller FFT size. Afterdigital-to-analog conversion (ADC), the signal is up converted to adesired carrier frequency that is typically the center of the sub-band.

In an embodiment of the present disclosure, the GPO system 102 isconfigured with millimeter wave (mmwave) having low PAPR, in thedownlink. Also, for GPO output waveform, the plurality of data 110associated with the plurality of users is multiplexed in time domaineither within OFDM symbols or over multiple distinct OFDM symbols.

In an embodiment, the communication system 100 performs multiplexing ofdifferent waveforms from different users, in downlink. The communicationsystem 100 is configured with GPO system 102 with BPSK to be applied toone group of users to enhance coverage. For other users, the GPO system102 with QPSK, may be applied. In an embodiment, for users who are inclose to the vicinity of the communication system or BS 100, OFDM may beused. The plurality of user's data, also referred as frame, is splitinto multiple zones, where a different waveform may be applied in eachzone. The zones may be configured in at least one of statically anddynamically. The communication system 100 may inform the users about thezone configuration in a broadcast channel. The different zones may usesame or different numerology, such as but not limited to subcarrierwidth, CP length, and the like.

FIG. 2 illustrates a block diagram of a receiver communication system200, in accordance with some embodiment of the present disclosure.

As shown in FIG. 2, the receiver communication system 200, is alsoreferred as a receiver system or receiver. The receiver 200 includes aprocessor 202, memory 204 and modules 206. The memory 204 may becommunicatively coupled to the processor 202. The processor 202 may beconfigured to perform one or more functions of the receiver 200 forreceiving the data. In one implementation, the receiver 200 may comprisemodules 206 for performing various operations in accordance with theembodiments of the present disclosure.

The modules 206 includes a Fourier transform (FT) module 210, subcarrierde-mapping module 212, an equalizer 214, an inverse Fourier transform(IFT) module 216, de-mux user data module 218, demodulation module 220and a channel decoder 222.

The Fourier transform module 210, also referred as a Discrete FourierTransform (DFT) module or fast Fourier transform (FFT) module, isconfigured to receive an input data 224 from a transmitter, andtransform the received input data from time domain into frequencydomain, to obtain a transformed data.

The subcarrier de-mapping module 212 is configured to perform thede-mapping operation on the transformed data, to obtain de-mapped dataand collect allocated subcarriers. Also, the subcarrier de-mappingmodule 212 is configured with an optional constellation de-rotationblock to perform constellation de-rotation on the de-mapped data.

The equalizer 214 is configured to use time domain processing andequalizing the de-mapped data and frequency domain input, applied withfrequency domain equalization to generate equalized samples of data. Forexample, when the modulation of the user data is BPSK modulation thatuses real-valued modulation, then the equalizer 214 uses a widely linear(WL) equalizer, that filters the signal and its complex-conjugatesuppress the inter symbol interference (ISI). The IFT module 216performs inverse Fourier transformation of equalized data to generatetime domain signal.

The de-mux user data module 218, is also referred as demultiplexingmodule, is configured to demultiplex the time domain signal to producede-multiplex data. The demodulation module 220, is configured to performdemodulation on the demultiplexed data and generate demodulated data.The demodulation may be one of BPSK demodulation and QPSK demodulation.

For QPSK modulation, the demodulation module 220 is configured withsequence estimation methods to mitigate the ISI and to reduce theperformance loss caused by the ISI and generate demodulated data. Also,for QPSK modulation, the equalizer 214 may be configured with a minimummean-squared-error decision-feedback equalizer (MMSE-DFE) pre-filter,the De-Mux user data module 218 may be inactive or disabled and the datademodulation may be performed jointly for all the user's data, usingsequence estimation.

The channel decoder 222, also referred as decoder, is configured toreceive demodulated data from the demodulation module 220, to performdecoding and produce an output data 228, also referred as decoded data,associated with a user. Also, the decoder 222 may be configured toperform least squares (LS) channel estimates on the demodulated data.

FIG. 3 shows a flowchart illustrating a method of generating a waveformusing communication system 100 as shown in FIG. 1, in accordance withsome embodiments of the present disclosure.

As illustrated in FIG. 3, the method 300 comprises one or more blocksfor generating a waveform in a communication network. The method 300 maybe described in the general context of computer executable instructions.Generally, computer executable instructions can include routines,programs, objects, components, data structures, procedures, modules, andfunctions, which perform functions or implement abstract data types.

The order in which the method 300 is described is not intended to beconstrued as a limitation, and any number of the described method blockscan be combined in any order to implement the method. Additionally,individual blocks may be deleted from the methods without departing fromthe spirit and scope of the subject matter described herein.Furthermore, the method can be implemented in any suitable hardware,software, firmware, or combination thereof.

At block 310, multiplexing is performed, by the communication system100, on a plurality of data 110, associated with the plurality of usersto generate multiplexed data. Each of the plurality of data 110 is oneof a binary phase shift keying (BPSK) sequence and quadrature phaseshift keying (QPSK) sequence. In an embodiment, each of the plurality ofdata 110 is modulated using a binary phase shift keying (BPSK)modulation, wherein the generated waveform by the communication system100 may have an optimized peak to average power ratio (PAPR).

In an embodiment, each of the plurality of data 110, associated with theplurality of users, is modulated using a quadrature phase shift keying(QPSK) modulation, wherein the generated waveform by the communicationsystem 100 may have an optimized peak to average power ratio (PAPR). Inan embodiment, the communication system 100 is configured such that eachof the plurality of data 110, associated with the plurality of users, ismodulated using one of binary phase shift keying (BPSK) and quadraturephase shift keying (QPSK) modulation.

At block 320, performing a rotation operation, by the rotation module130, configured in the communication system 100, on the multiplexed datato produce a rotated data. The rotation module 130 performs aconstellation rotation, to rotate each of the plurality of data by 90degrees. The constellation rotation operation performed on each of theplurality of input data produces a corresponding phase differencebetween each successive data associated with the plurality of data.

At block 330, transforming the rotated data by the DFT spreading module132, configured in the communication system 100, using Fourier transformto produce transformed data.

At block 340, mapping of the transformed data is performed by thefrequency domain filter 134, which is configured with subcarrier mappingwhich uses a predefined number of subcarriers to produce a mapped datasequence.

At block 350, processing the mapped data sequence to generate thewaveform. The processing is performed by the inverse Fourier transformmodule 136 on the mapped data sequence, to produce time domain signal.Further, the output module 138 performs at least one of addition ofcyclic prefix, cyclic suffix, windowing, windowing with overlap andadding operation, and frequency shifting on the time domain signal togenerate a waveform. In an embodiment, the output waveform 140 may befed to a digital to analog converter to generate analog precodedwaveform.

In an embodiment, the communication system 100 has applications such asmultiplexing of multiple user data in coverage limited systems or insystems where high-power amplifier (PA) efficiency is required. Also,other applications include, but not limited to, mmwave systems, cellularbase stations that need very large coverage, cellular base stations thatmay run on solar power that need high PA efficiency. Also, thecommunication system 100 may be used for low cost base stations thatneeds a lower cost PA.

Finally, the language used in the specification has been principallyselected for readability and instructional purposes, and it may not havebeen selected to delineate or circumscribe the inventive subject matter.It is therefore intended that the scope of the invention be limited notby this detailed description, but rather by any claims that issue on anapplication based here on. Accordingly, the disclosure of theembodiments of the invention is intended to be illustrative, but notlimiting, of the scope of the invention, which is set forth in thefollowing claims.

While various aspects and embodiments have been disclosed herein, otheraspects and embodiments will be apparent to those skilled in the art.The various aspects and embodiments disclosed herein are for purposes ofillustration and are not intended to be limiting, with the true scopeand spirit being indicated by the following claims.

The invention claimed is:
 1. A method of generating a waveform in acommunication network, the method comprising: multiplexing, by acommunication system, a plurality of data associated with a plurality ofusers, to generate multiplexed data, wherein the plurality of data issplit according to a plurality of zones, and wherein a differentwaveform is applied in each zone of the plurality of zones, and whereina user of the plurality of users is determined to be in a particularzone according to a proximity of the user to the communication system;performing a rotation operation, by the communication system, on themultiplexed data to produce a rotated data; transforming, by thecommunication system, the rotated data using Fourier transform toproduce transformed data; mapping, by the communication system, thetransformed data with a predefined number of subcarriers to produce amapped data sequence; and processing, by the communication system, themapped data sequence to generate the waveform.
 2. The method as claimedin claim 1, wherein each of the plurality of data is one of a binaryphase shift keying (BPSK) sequence and quadrature phase shift keying(QPSK) sequence.
 3. The method as claimed in claim 1, wherein each ofthe plurality of data, associated with the plurality of users, ismodulated using binary phase shift keying (BPSK) modulation, wherein thegenerated waveform comprises an optimized peak to average power ratio(PAPR).
 4. The method as claimed in claim 1, wherein each of theplurality of data, associated with the plurality of users, is modulatedusing quadrature phase shift keying (QPSK) modulation, wherein thegenerated waveform comprises an optimized peak to average power ratio(PAPR).
 5. The method as claimed in claim 1, wherein each of theplurality of data, associated with the plurality of users, is modulatedusing one of binary phase shift keying (BPSK) and quadrature phase shiftkeying (QPSK) modulation.
 6. The method as claimed in claim 1, whereinthe rotation operation performed is a constellation rotation, to rotateeach of the plurality of data by 90 degrees.
 7. The method as claimed inclaim 6, wherein the constellation rotation operation on each of theplurality of input data produces a corresponding phase differencebetween each successive data associated with the plurality of data. 8.The method as claimed in claim 1, wherein processing the mapped datasequence to generate a waveform comprising: performing an inversediscrete Fourier transform (IDFT) on the mapped data sequence togenerate mapped data sequence; and performing at least one of transmitblock selection operation, addition of cyclic prefix, addition of cyclicsuffix, windowing, windowing with overlap and add operation, andfrequency shifting on the mapped data sequence, to generate thewaveform.
 9. The method as claimed in claim 1, wherein the generatedwaveform is converted from digital form to analog form.
 10. Acommunication system to generate a waveform in a communication network,the system comprising: at least one transceiver, configured to performat least one of receiving a plurality of data from a transmitter, andtransmitting a generated waveform to a destination; a multiplexer,coupled with the at least one transceiver, configured to multiplex aplurality of data associated with a plurality of users and generatemultiplexed data, wherein the plurality of data is split according to aplurality of zones, and wherein a different waveform is applied in eachzone of the plurality of zones, and wherein a user of the plurality ofusers is determined to be in a particular zone according to a proximityof the user to the communication system; a memory; and a processor,communicatively coupled to the memory, configured to: perform a rotationoperation on the multiplexed data to produce a rotated data; transformthe rotated data using Fourier transform to produce transformed data;map the transformed data using a predefined number of subcarriers toproduce a mapped data sequence; and process the mapped data sequence togenerate a waveform.
 11. The system as claimed in claim 10, wherein eachof the plurality of data is one of a Binary Phase Shift Keying (BPSK)sequence and Quadrature Phase Shift Keying (QPSK) sequence.
 12. Thesystem as claimed in claim 10, wherein the processor is configured tomodulate each of the plurality of data, associated with the plurality ofusers, using binary phase shift keying (BPSK) modulation, wherein thegenerated waveform comprises an optimized peak to average power ratio(PAPR).
 13. The system as claimed in claim 10, wherein the processor isconfigured to modulate each of the plurality of data, associated withthe plurality of users, using quadrature phase shift keying (QPSK)modulation, wherein the generated waveform comprises an optimized peakto average power ratio (PAPR).
 14. The system as claimed in claim 10,wherein the processor is configured to modulate each of the plurality ofdata, associated with the plurality of users, using one of binary phaseshift keying (BPSK) and quadrature phase shift keying (QPSK) modulation.15. The system as claimed in claim 10, wherein the processor isconfigured to rotate each of the plurality of data by 90 degrees using aconstellation rotation.
 16. The system as claimed in claim 10, whereinthe processor is configured to process the mapped data sequence togenerate a waveform, by performing steps of: obtaining an inversediscrete Fourier transform (IDFT) on the mapped data sequence togenerate mapped data sequence; and performing at least one of transmitblock selection operation, addition of cyclic prefix, addition of cyclicsuffix, windowing, windowing with overlap and add operation, andfrequency shifting on the mapped data sequence, to generate thewaveform.
 17. The system as claimed in claim 10, wherein the processoris configured to rotate each of the plurality of data to produce acorresponding 180/Q phase difference between each successive dataassociated with the plurality of data, wherein Q is size of modulationalphabet.